Making and Using Compost Teas Lynne Carpenter-Boggs and Catherine Crosby Washington State University Dept. Crop and Soil Sciences Presentation Overview What is compost tea? Definitions Ingredients Uses Compost Tea as a fertilizer Overview Application methods Compost Tea as a Disease Suppressant Regulations Mechanisms Take Home Messages on Compost Tea Quality of materials Why use it How to use it Note: Any brand names mentioned or seen in this slide set are used for information and example only, and are not endorsements of any given product. Presentation Overview What is compost tea? Definitions Ingredients Uses 1
Compost Tea 1 part compost : 1-100 parts water May also contain Inoculants Sugars, microbe food Plant nutrients, rock powder Aerated or static fermentation 1hr-1wk Extracts soluble nutrients & humics Dislodges and grows microorganisms Passive Steeping Compost Extract or Non-aerated Compost Tea Brewing with Aerator Aerated Compost Tea Low cost Potential for anaerobic conditions (photo L. Carpenter-Boggs) Consistent aeration (photo L.M. Lege) Compost Water time Tea with water-soluble nutrients and dislodged microbes 2
How can we make different kinds of tea? Change the: Compost Aeration Temperature Additives More Compost Water Tea with More water-soluble nutrients and dislodged microbes Different Compost Water Tea with Different water-soluble nutrients and dislodged microbes 3
What are compost tea additives? Kelp extracts Humic acids Rock dust Molasses * Whey powder Dried herbs Commercial blends Photo credit: L. M. Lege *Addition of sugars can increase growth of E. coli and human pathogens Compost Water Added ingredients We cannot create elements. Nutrients come from ingredients or N fixation (not shown in teas) Tea with Added water-soluble nutrients and potentially different microbes Initial Compost Microbes Nutrients Temperature Oxygen status Compost Tea Microbes Good bugs in good bugs out Bad bugs in bad bugs out Danger in using poorly processed composts, esp. animal-based 4
We can grow and change the microbial community. In general, Food + warmth + time grows more microbes But microbes are diverse. Some foods and conditions will General Effects of Inoculants Enhanced Habitat Poor Habitat Inoculate Time We can make different teas from the same compost ph 9 8 Neutral 7 6 5 4 3 2 1 0 ph a b d c Protozoan A Diverse B Fungal C Bacterial D Tea Recipe Batch 1 Batch 2 Batch 3 5
We can make different teas from the same compost Electrical Conductivity 2 a ds m^-2 1.5 1 0.5 d b c Batch 1 Batch 2 Batch 3 0 Protozoan A Diverse B Fungal C Bacterial D Tea Recipe Why do we care about brewing different teas? Designing teas for specific uses Macronutrients and Micronutrients ph Microbial community Why use compost tea? Compost tea is gaining interest for its perceived ability to: enhance plant health suppress plant disease provide plant nutrients reduce fungicide and fertilizer requirements Research efforts to test these and other effects are expanding. 6
Presentation Overview Compost Tea as a fertilizer Overview Application methods Compost Tea as Fertilizer Compost teas contain Nitrogen Carbon Phosphorus Sulfur Potassium Micronutrients Inorganic N mg/l depends on additives etc. just not much 3.5 3 2.5 2 1.5 1 0.5 0 Total inorganic N Protozoan A Diverse B Fungal C Bacterial D Tea Recipe Compost Tea as Fertilizer Pak choi (4) Significantly improved Leaf size Above ground biomass by 20% Compared to chicken manure compost Not significantly different than soluble fertilizer Nutritional status Strawberry (2) Non-aerated teas provided same level of micronutrients as compost and fertilizer 7
Foliar or soil application Use full-strength or diluted up to 1:100 Compost Teas Directly onto crops to increase growth, supply nutrients, reduce pests & diseases.* *Compost tea is considered an experimental pesticide! Applied to soil to improve chemistry, nutrients, and biota Compost tea application Dilute tea up to 1:100 with water Check electrical conductivity (suggest under 0.5 ds/m) Use low pressure sprayer If concerned about damaging microbial cells Can be applied as a soil drench Through irrigation lines if filtered Does Foliar Feeding Work? A portion of a plant s nutritional needs can be met by applying soluble fertilizer directly to the foliage. Foliar fertilization can result in rapid nutrient absorption and utilization to correct deficiencies or to merely prevent nutrient shortages during critical periods of growth. However, unlike roots, plant leaves are not adapted to assimilate large amounts of nutrients and meet the bulk of the nutrient requirement. For some crops, foliar nutrition may be the most economical and reliable method of providing some nutrients, especially with micronutrients. International Plant Nutrition Institute https://www.ipni.net/ipniweb/pnt.nsf/5a4b8be72a35cd46852568d9001a18da/688627694f30cb 2e8525740c004c6971!OpenDocument 8
References (non-comprehensive) 1. Chang, K. H., R. Y. Wu, K. C. Chuang, T. F. Hsieh, and R. S. Chung, 2010, Effects of chemical and organic fertilizers on the growth, flower quality and nutrient uptake of Anthurium andreanum, cultivated for cut flower production: Scientia Horticulturae, v. 125, p. 434-441. 2. Hargreaves, J. C., M. S. Adl, and P. R. Warman, 2009, Are compost teas an effective nutrient amendment in the cultivation of strawberries? Soil and plant tissue effects: Journal of the Science of Food and Agriculture, v. 89, p. 390-397. 3. Lopez-Espinosa, S. T., A. Moreno-Resendez, P. Cano-Rios, N. Rodriguez-Dimas, V. Robledo-Torres, and C. Marquez-Quiroz, 2013, Organic fertilization: An alternative to produce jalapeno pepper under greenhouse conditions: Emirates Journal of Food and Agriculture, v. 25, p. 666-672. 4. Pant, A. P., T. J. K. Radovich, N. V. Hue, and S. C. Miyasaka, 2012, Pak Choi (Brassica rapa, Chinensis Group) Yield, Phytonutrient Content, and Soil Biological Properties as Affected by Vermicompost-to-water Ratio Used for Extraction: Hortscience, v. 47, p. 395-402. 5. St Martin, C. C. G., W. Dorinvil, R. A. I. Brathwaite, and A. Ramsubhag, 2012, Effects and relationships of compost type, aeration and brewing time on compost tea properties, efficacy against Pythium ultimum, phytotoxicity and potential as a nutrient amendment for seedling production: Biological Agriculture & Horticulture, v. 28, p. 185-205. Presentation Overview Compost Tea as a Disease Suppressant Regulations Mechanisms Results of Compost Tea Disease Control Studies MIXED!! Sometimes suppress disease Sometimes worsen disease Sometimes enhance plant growth Sometimes reduce harvestable yield Sometimes no effect 9
Pathogens and Diseases Reduced or Controlled with Compost Teas (at least 1 published research article) Common name Late blight of potato, tomato Gray mold on beans, strawberries Fusarium wilt Powdery mildew on cucumbers Apple scab Bacterial leaf blight on carrots Downy & powdery mildew on grapes Genus Phytophthora Botrytis Fusarium Sphaerotheca Venturia Xanthomonas Uncinula, Plasmopara References (non-comprehensive) Dionne, A., R. J. Tweddell, H. Antoun, and T. J. Avis, 2012, Effect of nonaerated compost teas on damping-off pathogens of tomato: Canadian Journal of Plant Pathology-Revue Canadienne De Phytopathologie, v. 34, p. 51-57. Kone, S. B., A. Dionne, R. J. Tweddell, H. Antoun, and T. J. Avis, 2010, Suppressive effect of non-aerated compost teas on foliar fungal pathogens of tomato: Biological Control, v. 52, p. 167-173. Pant, A. P., T. J. K. Radovich, N. V. Hue, and R. E. Paull, 2012, Biochemical properties of compost tea associated with compost quality and effects on pak choi growth: Scientia Horticulturae, v. 148, p. 138-146. Siddiqui, Y., S. Meon, R. Ismail, and M. Rahmani, 2009, Bio-potential of compost tea from agro-waste to suppress Choanephora cucurbitarum L. the causal pathogen of wet rot of okra: Biological Control, v. 49, p. 38-44. St Martin, C. C. G., W. Dorinvil, R. A. I. Brathwaite, and A. Ramsubhag, 2012, Effects and relationships of compost type, aeration and brewing time on compost tea properties, efficacy against Pythium ultimum, phytotoxicity and potential as a nutrient amendment for seedling production: Biological Agriculture & Horticulture, v. 28, p. 185-205. How might disease suppression work? Competition for resources Predation Antagonism Stimulation of Plant Responses Interference with disease lifecycle Hyphae of the fungus Arthrobotrys coiled around a hypha of a pathogenic fungus Rhizoctonia resulting in the death of the latter (1a); the hypha of Sclerotium parasitized (revealed by penetration hole) by a parasitic fungus, Trichoderma (1b) (Campbell 1989). 10
Systemic Acquired Resistance Plant vaccination stimulates plant response prior to pathogen attack 80 80 Defense 60 60 compounds: Phenolics, 40 40 Peroxidase, Chitinase, etc. 20 20 Pathogen Inoculation inducer +SiO4 no control inducer Live Plant Dead Plant 0 0 0 2 4 0 2 4 6 8 Days after treatment Systemic Acquired Resistance Presentation Overview Take Home Messages on Compost Tea Problems with Tea Quality of materials Legal standing Our Verdict 11
Problems with Compost Teas High variability in products and responses Some diseases are worsened Poor understanding of mechanisms and responses Quality Control Factors you can control Initial compost Use high-quality, mature compost from a reliable source Consistent tea-making, spray conditions Photo credit L.M. Lege Legal standing of compost tea No compost teas are currently registered with EPA as pesticides. It is illegal to sell compost tea as a pesticide. In research, it is an experimental pesticide. Can be used to promote plant health, not to treat disease. Can be used as a nutrition supplement. 12
National Organic Standards Board Compost Extract: Any mixture of compost, water, additives and adjuvants Held for less than 1 hour May be applied without restrictions Compost Tea: Any mixture of compost, water, additives and adjuvants Held for more than 1 hour Restrictions may apply National Organic Standards Board Compost tea must be made with potable water Equipment must be sanitized Must use organic compliant compost sources Compost tea without additives can be applied without restrictions Compost tea with additives can be applied using raw manure restrictions: 90 / 120 day harvest ban Compost teas from a single compost source can be tested to show they meet EPA standards for fecal bacterial and (if so) applied without restriction New compost batches must each be tested. OMRI Organic Materials Review Institute (a nonprofit organization, not a regulatory agency) OMRI lists 23 brand names of compost teas and similar materials. These are allowed (with the NOP restrictions and 90/120 day caveat when appropriate) for use as crop fertilizers. There are no brand name materials allowed for use as a crop protectant. However, Compost tea made on the farm may be used to suppress the spread of disease organisms. Compost tea sold for disease suppression must comply with all pesticide regulations. 13
What is our verdict on Compost Tea? Weak but valuable nutritional supplement Some contain plant hormones Some stimulate plant defense system Much more peer-reviewed research needed before specific recommendations are warranted Take home concepts on compost tea Research is showing that compost teas can provide benefits to plant nutrition and health EPA rules DO NOT allow use of compost teas to control disease Use HIGH QUALITY starting materials garbage in = garbage out Compost tea with added ingredients should be used like raw manure Thank You Please ask lots of questions! 14
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